Time-related change evaluation of the cerebrospinal fluid using postmortem CT.

Purpose: We retrospectively evaluated the cerebro-spinal fluid (CSF) CT density at the lateral ventricle to compare the postmortem intervals in cadavers.

Materials And Methods: The number of cadavers enrolled in this study was 189 (male 120, female 69). According to the estimated postmortem time, the cadavers were divided into 13 groups (postmortem day 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 7, 10, 14, 21, 30), and were also re-grouped into 3 groups according to the postmortem time-width: group A (postmortem day 0.5-2.5), group B (day 3-7), and group C (day 10-30). Comparisons between the CSF density and estimated postmortem time were also analyzed.

Results: The CSF density was around 20HU up to day 2.5, and it increased gradually after day 3. Day 3 and 4 presented higher CSF density than day 1 and 1.5 (p<0.05). Day 7 presented higher CSF density than day 3 (p<0.05). According to the postmortem time-width, the CSF density increased with postmortem time (p<0.05). The simple linear regression equations presented negative correlation between CSF density and estimated postmortem time, and R(2) was 0.119.

Conclusion: The CSF density increased, but not linearly, according to the postmortem time, and the 3rd postmortem day was the earliest time allowing the difference to be detected. The CSF density needs further evaluation to enable estimation of the postmortem time.